Certain representatives of Poaceae (Gramineae) family, which includes a plant with known medicinal characteristics, Elymus (Agropyron) repens, have been chosen for a study case of molecular taxonomic approach in the biodiversity domain. The resulted molecular variance has proven a relative good informational potential of the simple RAPD method: only one of the suggested arrangement of the Elymus taxa representatives was in accordance of the known morphological based classification.